Absorbent products such as disposable diapers typically have two end portions commonly termed waist portions. These each extend from one end edge of the absorbent product up to a central or crotch portion, and each of the portions may occupy about ⅓ of the length of the product.
Elastic material may be applied to absorbent product webs used for forming disposable absorbent diapers. Such elastic material may be applied in the rear waist portion and/or the front waist portion of the absorbent products which are to be produced from the absorbent product web.
WO-A-99/60967 discloses an elastically extensible waist region comprising a continuous belt together with side flaps which may be made elastic. The elasticity is provided by means of a layered structure consisting of a further elastic member, preferably laminated between layers of the absorbent product chassis. The elastic in the waist portion also extends continuously into an upper portion of the side flaps.
Elastic materials such as elastic laminates (i.e. a layer of elastic material laminated to at least one further non-elastic layer) are expensive compared to the majority of other materials in the product. Due to the high speed mass production techniques for absorbent products currently used, there is a constant effort to solve the problem of how to reduce not only the amount of material used but also the amount of waste of material.
The present invention seeks to overcome the above problems by a method of applying elastic material pieces to the waist portions of an absorbent product web, in both a cost-saving and efficient manner, whereby waste is also minimized.